Microwave runs (light on, turntable rotates, fan runs) but food does not heat at all.

Critical safety warning: The high-voltage section of a microwave is extremely dangerous. Do not attempt to service the magnetron, capacitor, transformer, or inverter unless you are a trained technician. The capacitor can retain a lethal charge even when unplugged.

• Basic user checks only: Verify that you are using microwave-safe cookware and that the load is appropriate (e.g., a cup of water). Avoid running the microwave empty.
• Listen and observe: If the unit sounds normal (fan and turntable) but there is no heating, the fault is almost certainly in the high-voltage circuit.
• Do not bypass safety devices: Never bypass door switches or fuses to "test" heating.
• Professional service: Contact a Miele-authorized service center to diagnose and replace the magnetron, inverter, or related components. These repairs require specialized tools and leak testing.